In message <200202181241.HAA05044@Sparkle.Rodents.Montreal.QC.CA> you write:

|> The 8530 is a fairly dumb chip;

I some respects, yes. I know enough about its predecessor (Z80-SIO)
to know that a) I do not want to implement a driver for it and b)

|> it demands service at least every
|> couple of characters on input, or input gets dropped.

but I thought that a real OS would use DMA for high speed serial
links anyway - configure "RxINT on first character", and have the
interrupt handler enable the DMA controller.

AFAIR the technical manual for the Z80 family always shows SIOs
in conjunction with DMAs.

	vb

PS: should we take this off the list since it's not really NetBSD/
    sparc related any more?